Boris Johnson has called for a change in the law. He wants to shift the burden of proof on those accused of travelling to Iraq and Syria to join ISIS. No longer will the prosecution be required to prove that they intended to join ISIS. Rather the accused will have to prove that they travelled there for innocent purposes.
There has been near universal condemnation of Boris's proposals. The Prime Minister called it a knee-jerk reaction. Nick Clegg was not a big fan either. In addition to rejecting his proposals commentators on both the left and the right have taken issue with Boris's statement that this was a “minor change” in the law. They argued that instead it was an attack on this hallowed principle that is the presumption of innocence. The fact Boris did not realise that was further proof that he is unfit to become Prime Minister.

However, Boris is completely right. Not about the substantive proposal but about the fact it represents a minor change in the law. The fact of the matter is that the presumption of innocence has in the past few decades been severely eroded. In 1935 we were told by the Lord Chancellor Viscount Sankey that “throughout the web of English criminal law one golden thread is always to be seen, that it is the duty of the prosecution to prove the prisoner's guilt” [1]. There were only two exceptions: (i) the defence of insanity and (ii) statutory exceptions.

How often did Parliament by statute make exceptions to this golden thread? Andrew Ashworth and Meredith Blake attempted to find out in 1996 [2]. They look at how many of the offences triable in Crown Courts derogated from the presumption of innocence. It was not 5%, 10% or 20%. Out of 540 offences, 219 involved some form of departure from the presumption of innocence. That's just over 40%! In the Magistrates' Courts the position was hardly better. There, the defendant bears the burden of proving “any exception, exemption, proviso, excuse or qualification” [3]. At this point one can ask whether the exception has swallowed the rule. So Boris was not wrong when he described it as a minor change in the law.

The situation has not really gotten better since 1996. Parliament continues to reverse the burden of proof on a number of offences. In one respect, however, the situation has gotten better. Previously, if Parliament imposed a reverse burden of proof the courts would just have to apply it. However, following the coming into force of the Human Rights Act, the courts have been able to de facto nullify some of those reverse burdens.

For example in R v Lambert [2001] UKHL 37, the House of Lords was considering a provision of the Misuse of Drugs Act which required a defendant found in possession of a package containing drugs to prove that he did not know that it contained drugs. If the defendant failed to discharge that burden he would be found guilty of possession of drugs. The House of Lords held that this was an unjustfied infringement of the presumption of innocence. So, this provision was read as merely requiring the defendant to adduce evidence that he did not know the package contained drugs. The burden would then be on the prosecution to prove beyond reasonable doubt that this evidence was untrue.

Those wanting to repeal the Human Rights Act (and withdrawn from the European Convention on Human Rights), whilst still adhering to the presumption of innocence, should think carefully about that.

In the meantime the outrage sparked by Boris's comments should be directed to adopting the proposal the Criminal Law Revision Committee made in 1972: that there should not be reverse burdens in English criminal law [4].